BiruLyu
5/25/2017 - 4:46 PM

111. Minimum Depth of Binary Tree.java

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def minDepth(self, root):
        """
        :type root: TreeNode
        :rtype: int
        """
        if not root:
            return 0;
        if not root.left:
            return self.minDepth(root.right) + 1;
        if not root.right:
            return self.minDepth(root.left) + 1;
        else:
            return min(self.minDepth(root.left), self.minDepth(root.right)) + 1;
          
          
"""
TESTCASES:
Input:
[]
[1]
[1,1]
[1,null,2]
[1,2,3,null,null,1,2,1,null,null,null,1]

Output:
0
1
2
2
2
"""
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public int minDepth(TreeNode root) {
        if (root == null){
            return 0;
        } else if(root.left == null) {
            return minDepth(root.right) + 1;
        } else if(root.right == null) {
            return minDepth(root.left) + 1;
        }
        return Math.min(minDepth(root.left), minDepth(root.right)) + 1;
    }
}


/*
[]
[1]
[1,1]
[1,null,2]
[1,2,3,null,null,1,2,1,null,null,null,1]
*/